Method of making troughs.



PATENTBD MAR. 5, 1907. PRUDEN.

F MAKING TROUGHS.-

ION FILED APR No. 846,139. G. D.

METHOD 0 APPLIOAT 3 P 3A g CLARENCE D. PRUDEN, OF ST. PAUL, MINNESOTA.

METHOD OF MAKING TROUGHS.

specification of Letters Patent.

Patented March. 5, 1907.

Aonlication filed April 15, 1904- Serial No. 203,277.

To all whom zit may concern:

Be it known that I, CLARENCE D. PRUDEN, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and useful Improvements in Method of Making Troughs, of which the following is a specification.

My invention relates to improvements in the method of making troughs, and particularly in the forming of a rolled edge therefor,

whereby lengths of trough can be more quickly and easily made than with the ordinary method.

In the accompanying drawings, forming part of this specification, Figures 1 and 2 are sectional views of the cooperating ends of dies with an interposed blank to form the trough, illustrating the first step of my improved method. Figs. 3 and 4 are similar views illustrating the second step of my improved method, and Figs. 5 and 6 are similar views showing a second set of dies and illustrating the third step.

In the drawings, 2 and 3 illustrate male and female dies, the male die being formed with a convex end 4 and the female die With a concave end 5. In carrying out the first step the edge of the blank 6 out of which the trough is formed is placed upon the female die and the dies brought together, as shown in Fig. 2, to form a curve 7 along the edge of the blank. The dies are then separated and the blank shoved forward, as shown in Fig, 3, when they are again brought together, as illustrated in Fig. 4, to form a curve 8 in the blank parallel to the edge curve 7. The blank is then removed from the dies, and the third and last step of the operation is accomplished by the dies 9 and 10. As shown, the

dies 9 and 10 have opposed concaved faces 11 and 12, with cooperating concave and convex surfaces, respectively, adjacent thereto. The blank is shown placed between the separated dies 9 and 10, as shown in Fig. 5, so that the edge curve 7 stands underneath the concave face 11 and the curved portion 8 stands in the concaved face 12. By then bringing the dies together, as illustrated in Fig. 6, the curves 7 and 8 0f the blank are forced together to form a completely-rolled edge corresponding in diameter to the diameter of the space formed by the concaved faces 11 and 12 of the dies when the dies are closed, the adjacent body of the blank being at the same time oppositely curved, as shown in the drawings.

It will be evident that the curves 7 and 8 must be formed in the blank at a certain distance from each other to allow them to be brought together by the dies 9'and 10 to form a rolled edge.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

The method of forming troughs, consisting of first forming a curve along one edge of the trough-blank, then forming a similar curve parallel to said edge curve, and then pressing said curved edge against said parallel curve portion to form a roll, and simultaneously and oppositely curving the adjacent body of the blank, for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

CLARENCE D. PRUDEN.

Witnesses:

H. S. JoHNsoN, EMILY F. OTIS. 

